Inspection Bulletin 2013-02 Antilock Brake Systems

Recently I have been noticing ABS trailer lamps going through the ignition cycle test and the ABS lamp on trailer will illuminate briefly and then go out as required. However, when the service brakes are applied, again the trailer's ABS lamp will come on and go off and you will hear the normal clicking of the self-test. I have noticed this only newer equipment. If the ABS system is going through the self-test when the brakes are applied would the system be functioning during the test when the trailer is being pulled down the road? The tractor had a Bendix brake system. I was unable to identify the type of brake system on the trailer. I reached out to a company that specializes in brake systems and they provided me additional information on the Bendix ABS System: “Bendix does the bulb and fault test like all other systems are required to do with the initial turning on the power. However, they have a modulator "Chuff" test that when brake pressure applied, a properly installed modulator valve will cause 5 rapid audible chuffs of air pressure".

: If the ABS brake system operating properly by running through the self-test when the service brakes are applied as well as when the key is turned to the “on” position the ABS Inspection bulletin needs to be updated to reflect this new self-test in order to ensure the company is not being incorrectly cited or they should be cited if the system is not functioning correctly.

The Inspection Bulletin 2013-02 needs to be updated to include this new self-test, on a Bendix system, if it is how the system is designed to function. Or if this 2nd self-test is improper and the ABS system is not functioning during the 2nd self-test which unit does the violation belong as well as how to cite it. If ABS technology has changed/advanced and they are actually working properly the Inspection Bulletin needs to be updated with this new information.